Default value of an attribute changes to different value in different environments(eConfigurator)

Dear Experts,

One of my customer is facing a peculiar issue with attribute values selection during product customization.

Description: Customer have a product EAD with SiteType defaulted at class level with a value "BT". Now they have preference rules written on this product as below:

SiteType  (LOV Based Attribute) is having following values
-->BT  (Defaulted on product Model class level)
-->Non BT


if SiteType = Non BT then

Rack-->NA
Suite-->NA


if SiteType = BT then
LLUCNumber-->NA

Now the expectation during loading values of eConfigurator as :

SiteType = BT
LLUCNumber-->NA
Rack (Blank defaulted at class level)
Suite (Blank defaulted at class level)